The present invention generally relates to a storage system and a data storage method, and in particular is suitably employed in a storage system required to store data for an extended period of time.
In the present age, storage systems are required to store large volumes of data for an extended period of time across the globe. Nevertheless, since data must be stored beyond the life span of an external storage apparatus, it is necessary to prevent the loss of data upon the occurrence of a failure such as a malfunction in the storage system itself, or upon the replacement of the storage system due to internal improvement.
Thus, Japanese Patent Laid-Open Publication No. H7-129331 (Patent Document 1) discloses technology for preventing loss of data by using the storage apparatuses in a storage system as a pair of active storage apparatus and backup storage apparatus. According to this technology, by determining the occurrence of a failure such as a malfunction of the storage apparatus beforehand, it is possible to switch the main apparatus from the active storage apparatus to the backup storage apparatus in advance.
In addition, Japanese Patent Laid-Open Publication No. 2005-301980 (Patent Document 2) disclosed technology for storing data by controlling the access from a host system to a storage system upon replacing the storage system for improvement, and recording a time stamp (current date and time) provided from a clock circuit inside the storage system as a log in a memory. According to this technology, it is possible to accurately grasp the operational status of the storage system at the present moment.